1. Field of the Invention
The present invention relates to a bottom structure of a bed which allows the bottom to be bent upward, forming a large curvature such that it does not cause a patient to feel any discomforting pressure. The present invention also relates to a bottom structure of a bed which allows a patient to experience minimum physical discomfort irrespective of his body size when the bottom structure of a bed is bent, forming a large curvature in the leg portion corresponding to the leg or knee position of the patient or forming a large curvature in the waist position of the patient.
2. Description of the Related Art
In many recent beds, the bottom structure is divided into a back portion, waist portion, leg portion, etc. to allow the back portion and/or the leg portion to be raised by a drive. In these beds the bottom structure can be bent upward to alter the position of the back portion or knee portion, using various mechanisms.
An ordinary bed structure has a waist portion and a leg portion simply joined. It can happen that the joint between the waist portion and the leg portion does not fit or suit the knee position of the patient whose body size does not conform to a standard bed, as a result one can feel physical discomfort when the leg portion of the bed is raised. To overcome this various beds having different positions of the bottom joint are required to be prepared.
An ordinary bed structure can also have a back portion and a waist portion simply joined. The joint acts as a pivot for the back portion, when raising and lowering the back portion. Therefore, as the back portion is raised to a certain angle, the space formed near the joint between the back portion and the waist portion becomes narrow. As a result, the waist and abdominal region of the patient are uncomfortably pressed by the mattress, which is bent at an angle.